Electric-light globe



M., A. BAMBOROUGH ET AL ELECTRI C LIGHT GLOBE Filed June 18, 1925rut-072s Elli (6' M 0 Patented Jan. 13, 1925.,

cars

MASON A. BAMBOROUGH AND HAROLD A. BAMBOROUGH, OF CHICAGO, ILLINOIS.

ELECTRIC-LIGHT GLOBE.

Application filed June 18, 1923.

To all whom it may concern:

Be it known that we, MASON A. BAM- BOROUGH and HAROLD A. BAMBOROUGI-I,both citizens of the United States, and residents of Chicago, CookCounty, Illinois, have invented eertain new and useful Improvements inElectric-Light Globes, of which the following is declared to be a full,clear, and exact description.

This invention relates to electric light globes, and its principalobject is to provide a globe of improved construction and having a novelshape whereby it may be formed of very thin material throughout, and iwhereby a maximunr efiicieney may be ob tained from the lamp containedin the globe.

Another object is to eliminate bright spots and dark spots in the globeand to provide one in which the light, issuing from the :l lamp, isdiffused in all directions whereby a soft mellow and bright light may beobtained. lVith these and other objects and advantages in view, thisinvention consists in an electric light globe, the side wall of whichtakes the form, in vertical, cross section, of double reverse curves,whereby annular, outwardly bulged portions are formed adj acent theupper and lower portions of the globe, the upper bulged portion beingapproximately directly over the lower bulged portion, and an inwardlybulged portion intermediate said outwardly bulged portions. Theinvention further consists in the several novel features hereinafterfully set forth and claimed.

The invention is clearly illustrated in the drawing accompanying thisspecification, in which:

Fig. 1 is a perspective view, looking from below, of an electric lightglobe embodying a simple form of the present invention; Fig. 2 is acentral, vertical section through the globe and showing in sideelevation, a shade holder, an electric light socket, and an elec- -15tric lamp, and Fig. 3 is a detail, horizontal section taken on the line3-3 of Fig. 2.

Referring to said drawing, which illustrates a simple embodiment of thepresent invention, the globe A, is shown as secured to and supported bya holder B, of common and well known construction, having the usual setscrews 6, for engagement with the neck a, of the globe. In the formshown, the holder B, is clamped upon an electric light socket C, by asuitable clamp, as is Serial No. 645,975.

well understood, and an electric lamp D, of the incandescent type issecured in the socket C and projects down into the interior of theglobe. In order to obtain a brilliant light, it is preferred to use anincandescent electric light lamp of the nitrogen type, although, ofcourse, this is not essential to the invention, broadly considered.

The shape of the walls of the globe is best seen in Fig. 2 where it willbe seen that the side wall (L in vertical section takes the shape of adouble reverse curve which merges into the bottom wall a? of the globe.The double reverse curve forms upper and lower outwardly bulged annularportions at, 5, and an inwardly bulged portion 6 intermediate theoutwardly bulged portions at, 5. The upper and lower bulged portions areapproximately in vertical alignment. The outwardly bulged portion lcurves upwards and inwards towards the center of the globe, as at 7,forming the top which merges into the flaring neck a. The loweroutwardly bulged portion 5 merges into a curved portion 8 which curvesdownward and inward towards the center of the globe and then curvesdownward, as at 9, finally merging into a reverse curve 10 whichcontinues on towards the other side of the globe, and the curved linesjust described continue throughout the entire top Wall, side wall andbottom wall of the globe. It will be noted that the outwardly bulgedportion 5 of the globe is of slightly less diameter than the outwardlybulged portion -l. which we find gives added etticiency to the globeprovided the diameters of the two out wardly bulged portions aresubstantially the same.

The point at which the source of light is normally located, isapproximately midway between the top and bottom walls of the globe, andthe crowns, or extreme outer places of the outwardly bulged portions,are approximately equidistant from said norn'ial source of light point.

The globe is fori'ned by blowing the glass in a mould, and because ofits peculiar shape, as above described, we are able to obtain a verythin wall, which makes the globe light, and yet, because of its shape,it is less liable to be broken or cracked from heat or jars. It is to beobserved that there are no sharp or abrupt places in the walls, but thatthe entire wall is composed of reverse Ill) curves. This feature isessential to secure the best results obtainable. The globe is made oftranslucent material as is customary.

One of the advantages of an electric light globe constructed inaccordance with the above description, is that its shape permits thewall of the globe to be blown thinner than other shapes. Anotheradvantage is that no hot spots are created in the wall, nor are thereany bright spots or dark spots, but the entire wall of the globedilfuses the light evenly. Another advantage is that a lamp of highwattage may be used in the globe.

and becauseof its shape, the intensely bright light is concealed andthoroughly diffused in all directions, thereby greatly increasing theefficiency of. the electric light globe. Another advantage is that thereis an even flow of light rays because of the peculiar shape given to thewalls of the globe. An-

7 other advantage is'that there are no sharp shadows cast from a lightcontained in a globe as above described, but the shadows are sottandunobjeotionable. Another advau tage,vas shown by actual test, is thatover 91 per cent efliciency is obtained from the source of light, whichmakes it possible/to ruse electric lamps of less wattage than is topoint out all of the invention disclosed herein. 7

e claim as new and Letters Patent:

1. An electric light globe formed of translucent material, the walls ofwhicharerelatively thin and of substantially even thickness throughout,and con'iprising top and bottom walls and a side wall, the top wallsloping outward and'downward and the side desire to secure by wallhaving an annular outwardly bulged upper portion and an annularoutwardly bulged lower portion, and there being an annular inwardlybowed portion in said side wall between and merging, along lines thatform an obtuse angle, into said outwardly bulged portions, the diameterof said inwardly. bowed' portion being slightly less than that of theoutwardly bulged lower portion. r

2. An electric light globe formed of translucent material, the Walls ofwhich are relatively thin and otsubstantially even thicltnessthroughout, and comprising top and bottom walls'and a side wall, the topwall sloping outward and downward and the side wall having an annularoutwardly bulged upper portion merging into said top wall and anannularoutwardly bulged lower por-' tion merging into said bottom wall, and

there being an annular inwardly bowed portion in said side wall betweenand merging along lines that 'form an obtuse angle, into said outwardlybulged portions, the diameter of said inwardlv bowed portion beingslightly less than that of the outwardly bulged lower portion. r

MASON A. BAMBOROUGH. HAROLD A. BAMBOROUGH.

